The following sequence of events would lead to a crash:
- Reader A is created.
- Reader A produces a frame (A0)
- Texture is resized.
- Reader B is created and reader A is scheduled to be closed.
- Reader A produces a frame (A1). This is skipped.
- Reader A is closed.
- Frame A0 is acquired.
Because we closed Reader A the frame A0 is invalid.
The fix is to not close Reader A when it is the last reader to produce a
frame.
Fixes internal bug b/318458306
718ac2c814